The Cold War: Superpower Tensions and Rivalries

How to Use This Guide

• Paper 2 World History Topic 12 covers the Cold War from its origins (1945) to the dissolution of the USSR (1991)
• Paper 2 is a 90-minute exam in which you write two essays, each worth 15 marks — one from Topic 12 and one from another World History topic (or both from Topic 12)
• This topic is identical for SL and HL students — both sit the same Paper 2 questions. HL students also sit Paper 3 (regional option), but that is separate
• The single most important rule: many questions ask you to refer to two or more Cold War crises or examples from more than one region. The Cold War was a global conflict — Europe, Asia, Latin America, and beyond all feature. Plan your case studies to span regions
• Exam Alerts flag the traps that cost marks in essays
• IB Tips highlight what examiners reward in extended responses
• Worked Examples provide model essay outlines for common question types

Aligned to IB History SL/HL World History Topic 12 — current syllabus

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Videos on this page: Overview — What Was the Cold War? · Origins and Conferences · Cold War Crises · Cuban Missile Crisis · Détente and End of the Cold War

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Watch: Overview — What Was the Cold War?

Crash Course · 13 min · The Cold War — origins, ideological conflict, nuclear arms race, and the global dimensions of the superpower rivalry

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Section 1: Theme 1 — Rivalry, Mistrust, and Accord

1.1 Origins of the Cold War: Ideological Differences

The Cold War (approximately 1947–1991) was a sustained geopolitical, ideological, and military rivalry between the United States and the Soviet Union. It was a “cold” war because the two superpowers never directly fought each other — the threat of nuclear annihilation made direct conflict too dangerous — but it produced dozens of proxy wars, crises, and confrontations around the world.

The ideological divide:

Dimension	United States	Soviet Union
Economic system	Capitalism — private ownership, free markets	Communism — state ownership, planned economy
Political system	Liberal democracy — multi-party elections, civil liberties	One-party state — Communist Party monopoly, no free elections
Foreign policy goal	Contain communism (“containment”); protect US economic access globally	Export revolution; create a buffer of friendly states; prevent capitalist encirclement
View of the other	The USSR was a totalitarian tyranny expanding world communism	The USA was a capitalist imperialist power seeking global economic domination

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1.2 Origins of the Cold War: Wartime Conferences and Post-War Disagreements

The Cold War did not begin suddenly in 1947 — its roots lie in wartime alliances and post-war power struggles.

The Wartime Conferences, 1943–1945

The three Allied leaders — Roosevelt (USA), Churchill (UK), and Stalin (USSR) — met at three key conferences to plan the post-war world:

Tehran (November–December 1943):

• Agreement to open a second front in Western Europe (D-Day, 1944)
• Broad agreement on post-war spheres of influence
• Stalin demanded a large buffer zone of friendly states in Eastern Europe — the Western Allies did not push back firmly

Yalta (February 1945):

• Germany to be divided into occupation zones (American, British, French, Soviet)
• Declaration on Liberated Europe — free elections to be held in Eastern Europe
• USSR agreed to enter the Pacific War against Japan after Germany’s defeat
• Poland’s borders shifted westward; a “broadly democratic” Polish government promised
• Key tension: The Declaration on Liberated Europe was a vague promise that Stalin had no intention of honouring; he was already installing pro-Soviet governments in Eastern Europe

Potsdam (July–August 1945):

• Attended by Truman (Roosevelt had died in April 1945), Churchill then Attlee, and Stalin
• Germany divided into zones and agreed to pay reparations; the Oder-Neisse line confirmed as Germany’s eastern border
• Key change: Truman had atomic bomb — he informed Stalin obliquely. The balance of power had shifted dramatically
• Deep disagreements over Poland, reparations, and Eastern Europe. No agreement on Germany’s long-term future
• Potsdam marked the beginning of open tensions — the wartime alliance was fraying visibly

Post-War Disagreements, 1945–1947

After World War II, US-Soviet disagreements multiplied rapidly:

• Eastern Europe: Stalin installed Soviet-controlled governments in Poland, Romania, Bulgaria, Hungary, and Czechoslovakia between 1945 and 1948, violating the Yalta Declaration. Churchill described it as an “Iron Curtain” descending across Europe (March 1946, Fulton, Missouri).
• Germany: The USA wanted a unified, economically reviving Germany to stabilise Europe. The USSR wanted a weak, divided Germany paying heavy reparations. The two visions were incompatible.
• Iran (1946): Soviet troops remained in northern Iran past the agreed withdrawal date; the USA and Britain pressured their withdrawal — one of the first Cold War confrontations.
• Greece and Turkey (1947): Communist insurgency in Greece; Soviet pressure on Turkey’s Straits. Britain could no longer afford to support Greece, transferring the burden to the USA — the immediate context for the Truman Doctrine.

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1.3 The Nature of the Cold War: Nuclear Arms Race

The development of nuclear weapons transformed international relations fundamentally. Once both superpowers had hydrogen bombs, direct war between them was suicidal — this is the concept of Mutually Assured Destruction (MAD).

Key milestones:

Date	Event
Jul 1945	USA tests first atomic bomb (Trinity test, New Mexico)
Aug 1945	USA drops atomic bombs on Hiroshima and Nagasaki
Aug 1949	USSR tests its first atomic bomb (Joe-1) — ending US nuclear monopoly
Nov 1952	USA tests first hydrogen bomb (Ivy Mike) — 500x more powerful than Hiroshima bomb
Aug 1953	USSR tests its first hydrogen bomb
Oct 1957	USSR launches Sputnik — first satellite; demonstrates ICBM capability
1962	Cuban Missile Crisis — closest point to nuclear war
1963	Partial Test Ban Treaty — atmospheric testing banned
1968	Nuclear Non-Proliferation Treaty (NPT)
1972	SALT I — first strategic arms limitation agreement

What the arms race produced:

• Deterrence: Neither side would launch a first strike because the other could absorb it and retaliate (second-strike capability). This made the Cold War “stable” in one sense — direct superpower war never occurred.
• Massive expenditure: Both superpowers devoted enormous resources to military spending, with economic consequences
• Proxy wars: Unable to fight each other directly, the superpowers fought through client states — Korea, Vietnam, Angola, Afghanistan
• Domestic anxiety: “Duck and cover” drills in US schools; Soviet civil defence preparations; nuclear anxiety shaped the culture of both societies

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1.4 The Nature of the Cold War: Alliances, Propaganda, and Espionage

Military Alliances

NATO (North Atlantic Treaty Organisation, April 1949):

• Formed in response to the Berlin Blockade and Soviet expansion in Eastern Europe
• Founding members: USA, Canada, UK, France, Belgium, Netherlands, Luxembourg, Norway, Denmark, Iceland, Italy, Portugal
• West Germany joined in 1955 (rearming Germany — this directly triggered the Warsaw Pact)
• Key clause: Article 5 — an attack on one member is an attack on all

Warsaw Pact (May 1955):

• Soviet response to West German rearmament and NATO expansion
• Members: USSR, East Germany, Poland, Czechoslovakia, Hungary, Romania, Bulgaria, Albania
• In practice, the Warsaw Pact was an instrument of Soviet control over Eastern Europe — Soviet forces intervened militarily in Hungary (1956) and Czechoslovakia (1968) using the Pact as cover

Propaganda

Both superpowers used propaganda extensively:

• USA: Voice of America, Radio Free Europe, United States Information Agency (USIA). Hollywood films (science fiction, westerns) implicitly promoted American values. The Marshall Plan (1947) was economic aid but also explicitly designed to demonstrate capitalism’s superiority over communism.
• USSR: Soviet propaganda portrayed the USA as an imperialist power exploiting workers worldwide. The “peace movement” globally was partly coordinated by Soviet intelligence. The Soviet space programme (Sputnik 1957, Gagarin 1961) served propaganda functions as much as scientific ones.

Espionage

Intelligence agencies became central to the Cold War:

• CIA (Central Intelligence Agency, USA, est. 1947): covert operations, propaganda, coup support — overthrew governments in Iran (1953), Guatemala (1954), and Chile (1973)
• KGB (Committee for State Security, USSR, est. 1954): intelligence collection, counterintelligence, suppression of dissent in Soviet bloc
• Major espionage cases: Julius and Ethel Rosenberg (US — passed atomic secrets to USSR, executed 1953); Kim Philby and the Cambridge Five (British double agents working for the USSR); the U-2 spy plane incident (1960 — Gary Powers shot down over the USSR, derailing a summit)

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Watch: Origins — Wartime Conferences and the Start of the Cold War

TED-Ed · 5 min · How did the Cold War start? — The shift from wartime alliance to superpower rivalry in four minutes

Quick Recall — Section 1

Try to answer without scrolling up:

1. What were the key disagreements at the Potsdam Conference (1945)?
2. What does MAD stand for and why did it shape the Cold War?
3. What was the difference between NATO and the Warsaw Pact in practice?

Reveal answers

1. Disagreements at Potsdam included: German reparations (the USSR wanted more than the USA would agree to), the borders and government of Poland, and the future political status of Eastern European states. Truman’s possession of the atomic bomb also shifted the power dynamic significantly.
2. MAD stands for Mutually Assured Destruction — the doctrine that a nuclear first strike by either superpower would result in a devastating retaliatory second strike, making nuclear war suicidal for both sides. It created a form of deterrence that made direct superpower conflict too dangerous, pushing competition into proxy wars and crises.
3. NATO was a genuine collective defence alliance with shared decision-making among members. The Warsaw Pact functioned largely as an instrument of Soviet control over Eastern Europe — as demonstrated when Soviet forces used it as a framework to crush the Hungarian Revolution (1956) and the Prague Spring (1968).

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Section 2: Theme 2 — Leaders and Nations

2.1 Key Leaders and Their Impact

The Cold War was shaped significantly by individual leadership decisions. Understanding each leader’s ideology, domestic context, and foreign policy approach is essential for essay questions asking about the role of individuals.

Harry S. Truman (USA, 1945–1953)

Truman defined the early Cold War framework. Inheriting the presidency after Roosevelt’s death (April 1945), he faced immediate decisions about the atomic bomb and Soviet expansion.

Key decisions and their significance:

• Atomic bombs on Japan (August 1945): Ended the Pacific War rapidly but began the nuclear age and demonstrated US technological superiority — a signal to Stalin as much as a military decision
• Truman Doctrine (March 1947): In requesting $400 million for Greece and Turkey, Truman announced the USA would support “free peoples who are resisting attempted subjugation by armed minorities or by outside pressures.” This was the formal declaration of containment — the US would resist Soviet expansion globally
• Marshall Plan (June 1947): $13 billion in economic aid to rebuild Western European economies. Explicitly designed to make communism less attractive. The USSR rejected it and prevented Eastern European states from participating
• Berlin Airlift (1948–49): Responded to the Soviet blockade with a sustained airlift, demonstrating US commitment to West Berlin without provoking direct conflict
• NATO formation (1949): Created the first peacetime military alliance in US history — a dramatic departure from pre-war isolationism

Joseph Stalin (USSR, 1924–1953)

Stalin’s Cold War policy was driven by two priorities: security (preventing another devastating invasion of the USSR) and ideology (expanding the socialist bloc).

Key Cold War actions:

• Imposition of Soviet control over Eastern Europe (1945–1948): Stalin installed Communist governments in Poland, Romania, Bulgaria, Hungary, and Czechoslovakia through a combination of electoral manipulation, political violence, and Soviet military pressure
• Berlin Blockade (June 1948–May 1949): In response to Western currency reform in Germany (the Deutschmark), Stalin ordered all road, rail, and canal links to West Berlin cut. The West responded with a successful airlift. Stalin backed down — the first major Cold War confrontation, ending in a Western victory
• Korean War (1950–1953): Stalin approved Kim Il-sung’s invasion of South Korea; provided military equipment and advisers. Soviet pilots flew missions against UN forces under Chinese cover
• The “Doctor’s Plot” (1952–1953): A fabricated conspiracy suggesting Jewish doctors were planning to kill Soviet leaders — likely the prelude to a new wave of purges before Stalin died in March 1953

Nikita Khrushchev (USSR, 1953–1964)

Khrushchev brought a dramatically different style — more volatile, unpredictable, and willing to gamble. His period in power saw both the most dangerous Cold War crisis (Cuba, 1962) and the first real moves toward dialogue.

Key decisions:

• “Secret Speech” (February 1956): Denounced Stalin’s “cult of personality” and the purges, opening a period of “de-Stalinisation.” This had paradoxical effects: it inspired the Hungarian uprising (1956) and alarmed China (contributing to the Sino-Soviet split)
• Berlin Ultimatum (November 1958): Issued an ultimatum demanding the Western powers leave West Berlin within six months. The ultimatum was not acted upon — Berlin remained a flashpoint until the Wall was built in 1961
• Berlin Wall (August 1961): The East German government (with Soviet approval) built a wall sealing East Berlin — stopping the haemorrhage of skilled workers fleeing to the West (3.5 million had fled since 1945). The Wall became the defining symbol of the Cold War
• Cuban Missile Crisis (October 1962): Authorised the placement of Soviet nuclear missiles in Cuba. When discovered by US surveillance, the result was the most dangerous confrontation of the Cold War
• Removed from power (October 1964): Khrushchev’s Cuban missile gamble and erratic decision-making led to his ousting by the Politburo

John F. Kennedy (USA, 1961–1963)

Kennedy’s brief presidency contained two defining Cold War moments:

• Bay of Pigs invasion (April 1961): A CIA-backed invasion of Cuba by anti-Castro exiles failed disastrously. Kennedy refused to provide US air support. The fiasco strengthened Castro, emboldened Khrushchev, and humiliated the USA
• Cuban Missile Crisis (October 1962): Kennedy’s response — naval “quarantine” (blockade), ultimatum to Khrushchev, back-channel negotiations, and refusal to be pressured into immediate military action — is widely studied as a model of crisis management
• Test Ban Treaty (1963): Following Cuba, Kennedy and Khrushchev agreed to ban atmospheric nuclear testing — a first step toward arms control

Richard Nixon and Henry Kissinger (USA, 1969–1974)

Nixon’s presidency transformed the Cold War through détente — a deliberate relaxation of superpower tensions.

Key contributions:

• Opening to China (1972): Nixon’s visit to Mao’s China normalised US-Chinese relations after 23 years of hostility. This was a brilliant strategic move — triangular diplomacy played the USSR and China off against each other
• SALT I (1972): Strategic Arms Limitation Talks — the first arms control agreement between the superpowers, limiting ICBMs and submarine-launched ballistic missiles
• Nixon Doctrine (1969): The USA would provide military equipment and economic aid to allies, but they must provide their own troops — a response to the Vietnam debacle

Leonid Brezhnev (USSR, 1964–1982)

Brezhnev presided over a period of Soviet expansion but also the beginning of Soviet stagnation.

Key actions:

• Brezhnev Doctrine (1968): Following the Prague Spring, Brezhnev declared that the USSR had the right to intervene in any socialist state where socialism was threatened. This doctrine justified Soviet interventions within the bloc and alarmed non-aligned states
• SALT I and II: Brezhnev was the Soviet negotiator for both arms limitation agreements
• Invasion of Afghanistan (December 1979): The Soviet decision to intervene in Afghanistan to prop up a faltering Communist government was arguably the worst strategic decision of the late Cold War — it produced a decade-long war that the USSR could not win, at enormous cost

Ronald Reagan (USA, 1981–1989)

Reagan marked a dramatic reversal of détente — returning to a more confrontational Cold War posture.

Key actions:

• Reagan Doctrine: The USA would support anti-Communist resistance movements worldwide — applied in Afghanistan (arming the Mujahideen against the USSR), Nicaragua, and Angola
• Strategic Defense Initiative (SDI, “Star Wars,” 1983): Proposed a space-based missile defence shield. The USSR could not afford to match it. SDI significantly increased pressure on the Soviet economy
• Characterised USSR as an “Evil Empire” (March 1983): Rhetorically, Reagan abandoned the détente language of his predecessors
• Intermediate-Range Nuclear Forces (INF) Treaty (1987): Despite his confrontational rhetoric, Reagan ultimately negotiated the most sweeping arms reduction agreement of the Cold War with Gorbachev — eliminating an entire class of nuclear weapons

Mikhail Gorbachev (USSR, 1985–1991)

Gorbachev is arguably the single individual most responsible for ending the Cold War. His reforms, intended to save the Soviet system, instead destabilised and ultimately ended it.

Key actions:

• Glasnost (“openness”): Relaxed censorship, allowed criticism of the Soviet government and history (including Stalin’s crimes). This unleashed forces Gorbachev could not control
• Perestroika (“restructuring”): Economic reform — allowing limited private enterprise and decentralising economic decisions. But it produced chaos rather than growth
• New Political Thinking: Explicitly abandoned the Brezhnev Doctrine. Gorbachev stated the USSR would not use force to maintain Communist governments in Eastern Europe — this was the signal that allowed the revolutions of 1989 to occur
• INF Treaty (1987) and START I (1991): Major arms reduction agreements with the USA
• Did not order the military to suppress the 1989 revolutions: When Communist governments fell in Poland, Hungary, East Germany, Czechoslovakia, Romania, and Bulgaria, Gorbachev did not order Soviet intervention. This was the decisive difference from 1956 (Hungary) and 1968 (Czechoslovakia)

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Quick Recall — Section 2

Try to answer without scrolling up:

1. What was the Truman Doctrine and why was it significant?
2. What was the Brezhnev Doctrine and when was it effectively abandoned?
3. How did Gorbachev’s domestic reforms contribute to the end of the Cold War?

Reveal answers

1. The Truman Doctrine (March 1947) was Truman’s declaration that the USA would support free peoples resisting Communist subjugation, announced when requesting aid for Greece and Turkey. It was significant because it formalised the policy of “containment” and committed the USA to a global anti-Communist role — marking the end of pre-war American isolationism.
2. The Brezhnev Doctrine (1968) stated the USSR had the right to intervene militarily in any socialist state where socialism was threatened. It was effectively abandoned by Gorbachev in 1989, when he refused to use force to maintain Communist governments in Eastern Europe, allowing the revolutions of 1989 to proceed without Soviet intervention.
3. Glasnost (openness) relaxed censorship and allowed criticism of the Soviet past, unleashing nationalist movements in Soviet republics and pressure for political change that Gorbachev could not control. Perestroika (economic restructuring) failed to produce growth and created economic confusion. Both reforms undermined the legitimacy and coherence of the Soviet state, accelerating its collapse.

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Section 3: Theme 3 — Cold War Crises

3.1 The Berlin Blockade, 1948–1949

Berlin, situated deep inside the Soviet zone of Germany, was divided into four occupation zones (American, British, French, and Soviet). The Western powers’ zones formed West Berlin — a capitalist island in Soviet-controlled territory.

Background:

• Western powers introduced a new currency, the Deutschmark, in their German zones (June 1948) to stabilise the economy — the old Reichsmark was worthless
• Stalin saw the currency reform as a step toward a permanently divided Germany aligned with the West

The Blockade (June 24, 1948):

• Stalin ordered all road, rail, and canal links between West Germany and West Berlin cut
• 2.5 million West Berliners had only six weeks of food supplies
• Soviet calculation: the West would be forced to abandon West Berlin or accept Soviet terms on Germany

The Airlift:

• USA and UK organised a massive airlift — eventually averaging 4,700 tonnes of supplies per day at its peak
• Over 277,000 flights were made in 11 months
• The airlift demonstrated that the West could sustain West Berlin indefinitely
• Stalin lifted the blockade on May 12, 1949 — a complete Western victory

Consequences:

• NATO formed (April 1949) — the blockade convinced Western European nations that a military alliance was necessary
• Germany permanently divided: Federal Republic of Germany (West, May 1949) and German Democratic Republic (East, October 1949)
• The West demonstrated resolve: it would not be intimidated out of its positions

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3.2 The Korean War, 1950–1953

Korea had been divided at the 38th parallel after World War II — the USA occupied the south, the USSR the north. Two rival Korean states emerged: the Republic of Korea (South) and the Democratic People’s Republic of Korea (North, under Kim Il-sung).

Outbreak (June 25, 1950):

• North Korean forces, with Stalin’s approval and substantial Soviet military equipment, crossed the 38th parallel in a massive conventional invasion
• South Korean forces collapsed rapidly — the USA intervened immediately under a UN Security Council resolution (the USSR was boycotting the Council over the China seat issue and could not veto)

The UN/US Counteroffensive:

• General Douglas MacArthur commanded UN forces — predominantly American
• After initial retreat to the Pusan Perimeter, a brilliant amphibious landing at Inchon (September 1950) cut off North Korean supply lines
• UN forces swept north, crossing the 38th parallel and advancing toward the Chinese border (Yalu River)

Chinese Intervention (October 1950):

• China sent 300,000 “People’s Volunteers” across the Yalu, driving UN forces back south of the 38th parallel
• MacArthur advocated bombing Chinese territory and using Nationalist Chinese forces — Truman fired him for publicly challenging presidential authority (April 1951)

Stalemate and Armistice:

• Fighting stabilised roughly along the 38th parallel from mid-1951 onwards
• Armistice signed at Panmunjom, July 27, 1953 — essentially restoring the pre-war border
• Casualties: approximately 36,000 US military dead, 2–3 million Korean civilian dead, 600,000 Chinese military dead

Significance for the Cold War:

• Demonstrated US willingness to fight for containment in Asia
• Brought China and the USA into direct military confrontation — hostility that lasted until Nixon’s China visit (1972)
• Accelerated US military spending and NATO rearmament
• Showed the limits of the UN as a collective security organisation — it depended on US military power

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3.3 The Cuban Missile Crisis, October 1962

The Cuban Missile Crisis is widely considered the closest the world came to nuclear war. Understanding it requires understanding the prior events that set the stage.

Background:

• Cuba’s Fidel Castro had overthrown the Batista dictatorship in 1959 and, by 1961, declared Cuba a socialist state aligned with the USSR
• Bay of Pigs (April 1961): CIA-backed invasion by Cuban exiles failed humiliatingly — Kennedy’s refusal to provide US air support doomed it. Castro was strengthened, Khrushchev emboldened
• Khrushchev decided to place Soviet medium-range ballistic missiles (MRBMs) and intermediate-range ballistic missiles (IRBMs) in Cuba — partly to defend Cuba, partly to address the strategic imbalance (the USSR was far behind the USA in intercontinental ballistic missiles), and partly to use as a bargaining chip over Berlin

The Crisis:

• October 14, 1962: US U-2 spy plane photographs reveal Soviet missile construction sites in Cuba
• October 16: Kennedy informed; forms ExComm (Executive Committee of the National Security Council) to manage the crisis secretly
• ExComm debate: Military advisers push for air strikes and invasion; Kennedy opts for a naval “quarantine” (blockade) of Cuba
• October 22: Kennedy goes on television, reveals the missiles, announces the quarantine, and demands the USSR remove them
• October 24: Soviet ships approach the quarantine line — then stop. Khrushchev has ordered them to halt
• October 27, “Black Saturday”: A U-2 is shot down over Cuba; ExComm is under pressure to retaliate; a Soviet submarine (B-59) nearly fires a nuclear torpedo (was only prevented because one officer, Vasili Arkhipov, refused to authorise the launch)
• Resolution: Khrushchev agreed to remove Soviet missiles from Cuba; Kennedy secretly agreed to remove US Jupiter missiles from Turkey and gave a pledge not to invade Cuba

Consequences:

• Moscow-Washington “Hotline” (June 1963): A direct communication link established to prevent future crises from escalating through miscommunication
• Partial Test Ban Treaty (August 1963): Atmospheric nuclear testing banned
• Khrushchev’s prestige damaged; he was removed in 1964 partly because of the Cuban gamble
• Cuba remained a socialist state and Soviet ally, but the direct nuclear confrontation was resolved

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Watch: The Cuban Missile Crisis — Thirteen Days

Crash Course · 13 min · The Cuban Missile Crisis — what happened, why it almost led to nuclear war, and how it was resolved

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3.4 The Vietnam War, 1955–1975

Vietnam was one of the most significant Cold War proxy conflicts — the USA’s longest war until Afghanistan and a major contributor to the collapse of the containment consensus.

Background:

• Vietnam had been divided at the 17th parallel in 1954 following French defeat at Dien Bien Phu — a communist North (Democratic Republic of Vietnam under Ho Chi Minh) and a US-backed South (Republic of Vietnam)
• The Geneva Accords (1954) called for national elections in 1956, which the USA and South Vietnam refused to hold (fearing Ho Chi Minh would win)
• The National Liberation Front (NLF/Viet Cong) — a communist insurgency in South Vietnam — grew rapidly from the late 1950s, supported by the North

US Escalation:

• Eisenhower: Sent military advisers and financial aid to South Vietnam; committed the USA to preventing a communist takeover
• Kennedy: Increased advisers to 16,000; debated but did not order direct combat intervention
• Gulf of Tonkin incident (August 1964): Alleged North Vietnamese attacks on US destroyers in the Gulf of Tonkin (the second “attack” almost certainly did not occur). The Gulf of Tonkin Resolution gave Johnson near-unlimited authority to use military force in Vietnam
• Johnson: Escalated from 16,000 advisers (1963) to over 500,000 troops (1969); strategic bombing of North Vietnam (Operation Rolling Thunder); search and destroy operations; the war became deeply unpopular domestically

The Tet Offensive (January–February 1968):

• North Vietnamese and Viet Cong forces launched simultaneous attacks on over 100 South Vietnamese cities and towns during the lunar new year (Tet)
• Militarily defeated quickly by US and South Vietnamese forces, but the psychological and political impact was devastating — it proved the war was not nearly won, as the US government had claimed

Nixon and Vietnamisation:

• Nixon’s strategy was “Vietnamisation” — training South Vietnamese forces to take over the fighting while the USA withdrew
• US troop withdrawal alongside secret bombing of Cambodia and Laos
• Paris Peace Accords (January 1973): US withdrawal from Vietnam; North Vietnamese forces allowed to remain in South Vietnam — effectively sealing South Vietnam’s fate

Fall of Saigon (April 30, 1975):

• North Vietnamese forces conquered South Vietnam; the country was reunified under communist rule as the Socialist Republic of Vietnam

Significance:

• 58,000 US military deaths; estimates of 2–3 million Vietnamese deaths (military and civilian)
• The USA’s first military defeat
• Demonstrated the limits of conventional superpower military force against guerrilla insurgency
• The “Vietnam Syndrome” — US public reluctance to commit troops abroad — shaped US policy for years

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3.5 The Prague Spring, 1968

Background:

• Czechoslovakia was one of the most economically developed Soviet-bloc states but was under rigid Communist Party control
• In January 1968, Alexander Dubcek became First Secretary of the Czechoslovak Communist Party and launched a programme of reform

“Socialism with a Human Face”:

• Dubcek proposed “Socialism with a Human Face” — maintaining the one-party state and Warsaw Pact membership, but with:
  • Freedom of speech and press
  • Rehabilitation of victims of Stalinist purges
  • Greater autonomy for Slovakia
  • Economic decentralisation

Soviet Response:

• The USSR and other Warsaw Pact leaders feared that Czechoslovak reforms would spread to other bloc states
• August 20–21, 1968: Warsaw Pact forces (primarily Soviet, with Polish, East German, Bulgarian, and Hungarian units) invaded Czechoslovakia — 250,000 troops
• Dubcek was arrested, taken to Moscow, and forced to reverse the reforms
• “Normalisation” followed — systematic suppression of the reform movement

The Brezhnev Doctrine (September 1968):

• The invasion was justified by the Brezhnev Doctrine: the USSR had the right to intervene to protect socialism in any socialist state

Significance:

• Demonstrated the rigid limits of reform within the Soviet bloc
• Disillusioned many Western European Communist parties and intellectuals (the “Eurocommunist” split)
• Contributed to the Sino-Soviet split — China condemned the invasion
• Contrast with 1989: Gorbachev’s refusal to repeat this intervention in 1989 was the decisive difference that allowed the peaceful revolutions to succeed

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3.6 The Soviet Invasion of Afghanistan, 1979–1989

Background:

• Afghanistan had a Communist government (PDPA) that came to power in a coup in 1978
• Factional fighting within the PDPA, a rural insurgency by Islamic Mujahideen (“holy warriors”), and the government’s brutal and incompetent policies had produced near-collapse by 1979

The Invasion (December 24–27, 1979):

• Soviet special forces killed the Afghan leader Hafizullah Amin (whom the USSR distrusted as potentially pro-American)
• Soviet forces entered Afghanistan; Babrak Karmal installed as a pro-Soviet leader
• The USSR expected a short stabilisation operation — it lasted nearly a decade

The War:

• The Mujahideen waged an effective guerrilla war against Soviet forces
• The USA, under Carter (immediately) and Reagan (massively), provided weapons, funding, and training to the Mujahideen through Pakistan’s ISI intelligence service — operation Codename Cyclone
• US-supplied Stinger anti-aircraft missiles proved particularly effective against Soviet helicopters from 1986
• Saudi Arabia co-funded the Mujahideen; thousands of Arab volunteers joined, including Osama bin Laden

Soviet Withdrawal (1988–1989):

• Gorbachev decided Afghanistan was an unwinnable “bleeding wound”
• Geneva Accords (April 1988) agreed a Soviet withdrawal
• Last Soviet troops left February 15, 1989

Consequences:

• 15,000 Soviet military deaths; estimated 1–2 million Afghan civilian deaths; 5 million Afghan refugees
• A major contributing factor to the collapse of Soviet prestige and economic overextension
• Contributed to Gorbachev’s decision to pursue reform and end the Cold War
• The Mujahideen factions subsequently fought a civil war; the Taliban emerged from this chaos — direct long-term consequences for the post-Cold War world

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Watch: Cold War Crises — Berlin, Cuba, Vietnam, Afghanistan

OverSimplified · 17 min · The Cold War — proxy conflicts, crises, and the global dimensions of the superpower rivalry explained clearly

Quick Recall — Section 3

Try to answer without scrolling up:

1. Why did the USA intervene in Korea in 1950, and what was the outcome?
2. What was the secret concession Kennedy made to resolve the Cuban Missile Crisis?
3. What was the Brezhnev Doctrine and how did it relate to the Prague Spring?

Reveal answers

1. The USA intervened in Korea to defend South Korea from the North Korean invasion (approved by Stalin) under the policy of containment — resisting communist expansion. The outcome was a military stalemate and armistice (July 1953) that essentially restored the pre-war border at the 38th parallel. The war demonstrated the USA’s willingness to fight for containment in Asia but also the limits of military action against Chinese intervention.
2. Kennedy secretly agreed to remove US Jupiter nuclear missiles from Turkey within a few months of the crisis resolution. This was publicly denied at the time — the Soviets agreed not to publicise it, to avoid embarrassing Kennedy. The removal of the Jupiter missiles was announced later as a routine NATO decision.
3. The Brezhnev Doctrine, announced after the invasion of Czechoslovakia in August 1968 (the Prague Spring), stated the USSR had the right to intervene militarily in any socialist state where socialism was threatened. It provided the ideological justification for the invasion that crushed Dubcek’s reforms. It was effectively abandoned by Gorbachev in 1989 when he refused to authorise Soviet military intervention to defend Communist governments in Eastern Europe.

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Section 4: Theme 4 — Détente and the End of the Cold War

4.1 Reasons for Détente

Détente (from the French word for “relaxation” or “easing of tension”) describes the period of improved US-Soviet relations, roughly 1969–1979, characterised by summits, arms control agreements, and a reduction in direct confrontation.

Why did both sides want détente?

American motivations:

• Vietnam had shown the limits of military containment — the USA needed a more sustainable strategy
• The US economy was under strain from military spending
• Nixon and Kissinger pursued a realist foreign policy — ideological confrontation was less important than stable power management. “Détente” recognised the USSR as a permanent strategic reality, not a regime to be overthrown
• Triangular diplomacy: by improving relations with both the USSR and China simultaneously, the USA could play them off against each other

Soviet motivations:

• The USSR faced a growing challenge from China — Sino-Soviet relations had split in the early 1960s and reached open hostility (border clashes, 1969). A hostile China on its eastern border while confronting the USA in the west was unsustainable
• Soviet economic growth was slowing; the USSR wanted access to Western technology and grain
• Nuclear parity with the USA (roughly achieved by the late 1960s) meant the USSR had more to gain from arms control — it could now negotiate from a position of approximate equality
• The Brezhnev leadership was inherently conservative and preferred managing the status quo to risky confrontation

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4.2 Arms Control Agreements

SALT I (Strategic Arms Limitation Talks I, 1972):

• Signed by Nixon and Brezhnev in Moscow, May 1972
• Froze the number of intercontinental ballistic missiles (ICBMs) and submarine-launched ballistic missiles (SLBMs) at existing levels
• Also produced the Anti-Ballistic Missile (ABM) Treaty — limiting missile defence systems
• Significance: First bilateral arms control agreement; recognised approximate strategic parity; created a framework for future negotiations

SALT II (1979):

• Signed by Carter and Brezhnev in Vienna, June 1979
• Set equal ceilings on total nuclear delivery vehicles (missiles, bombers) for both sides
• Never ratified by the US Senate — Carter withdrew the treaty from consideration after the Soviet invasion of Afghanistan (December 1979)
• The treaty was observed informally by both sides until Reagan abandoned it in 1986

Helsinki Accords (1975):

• Signed at the Conference on Security and Cooperation in Europe (CSCE)
• Three “baskets”:
  1. Security: Recognised existing European borders (crucially, the post-WWII borders of Eastern Europe) — a major Soviet goal
  2. Economic cooperation: Trade and technology exchange — what the USSR wanted
  3. Human rights: Signatories committed to respect human rights and fundamental freedoms — what the West inserted
• Long-term significance: The human rights provisions gave legal standing to dissident movements in Eastern Europe and the USSR. Groups like Charter 77 in Czechoslovakia and Solidarity in Poland used Helsinki commitments to demand their governments’ compliance. The Helsinki Accords are seen, in retrospect, as a crucial long-term factor in the collapse of the Soviet bloc.

INF Treaty (Intermediate-Range Nuclear Forces, December 1987):

• Signed by Reagan and Gorbachev in Washington
• Eliminated all ground-launched ballistic and cruise missiles with ranges of 500–5,500 km
• The first agreement to actually eliminate an entire class of nuclear weapons (SALT I and II had only set ceilings)
• Required on-site verification inspections — a dramatic departure from previous arms control agreements
• Signalled that the Cold War was genuinely winding down

START I (Strategic Arms Reduction Talks I, July 1991):

• Signed by Bush and Gorbachev five months before the USSR dissolved
• First agreement to actually reduce (not merely cap) strategic nuclear warheads
• Required each side to reduce strategic nuclear warheads to 6,000 and delivery vehicles to 1,600

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4.3 The Collapse of Détente

Détente collapsed between 1977 and 1980 under the weight of continuing superpower competition.

Contributing factors:

• Soviet activism in Africa: The USSR and Cuba intervened in Angola (1975–76) and Ethiopia (1977–78), supporting Marxist movements. This alarmed the USA and showed that détente had not stopped Soviet expansion
• Human rights pressure: Carter elevated human rights as a foreign policy priority, explicitly criticising Soviet treatment of dissidents — the USSR saw this as interference in internal affairs and a violation of détente’s spirit
• Neutron bomb controversy (1978): Carter cancelled production of the neutron bomb (an enhanced radiation weapon) after West European allies had reluctantly agreed to accept it — this made the USA appear unreliable
• SALT II ratification failure: Even before Afghanistan, the Senate was sceptical of SALT II — some senators saw it as too favourable to the USSR
• Iranian Revolution (1979): The fall of the Shah of Iran removed a key US ally in the Middle East, increasing superpower competition in the region
• Soviet invasion of Afghanistan (December 1979): The decisive event. Carter called it “the most serious threat to world peace since World War II” — an overstatement, but indicative of the shift in US policy. Carter imposed grain embargoes, boycotted the 1980 Moscow Olympics, and withdrew SALT II from Senate ratification

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4.4 Gorbachev’s Reforms and the End of the Cold War

Mikhail Gorbachev came to power in March 1985 inheriting an economy in serious difficulty: stagnant growth, declining oil revenues, massive military spending, and the unwinnable war in Afghanistan.

Glasnost (openness):

• Relaxed censorship; allowed public debate and criticism of the government
• Permitted discussion of Soviet historical crimes — the Gulag, the purges, the Molotov-Ribbentrop Pact
• Released political prisoners
• Paradoxically: glasnost empowered national independence movements in the Baltic states (Estonia, Latvia, Lithuania), Ukraine, and elsewhere — movements Gorbachev did not want to encourage

Perestroika (restructuring):

• Attempted to reform the Soviet economy by allowing limited private enterprise and decentralising some economic decisions
• In practice: produced economic disruption without generating growth; shortages worsened
• The command economy was too deeply embedded to be reformed incrementally

“New Political Thinking”:

• Gorbachev explicitly rejected the Brezhnev Doctrine
• Announced that Eastern European states could choose their own path
• Agreed to major arms reductions (INF Treaty 1987, START I 1991)
• Withdrew Soviet forces from Afghanistan (1988–1989)

Why the Cold War ended: historiographical debate

Explanation	Key Arguments	Associated Figures
Reagan “won” it	US military buildup and SDI bankrupted the USSR; Reagan’s confrontational strategy forced Soviet collapse	Conservative historians, Schweizer
Gorbachev ended it	Without Gorbachev’s deliberate choices — especially not using force in 1989 — the Cold War would have continued or ended violently	Archie Brown, most Western historians
Long-term Soviet overextension	The USSR’s economic model was unsustainable; Afghanistan, arms race, and bloc costs eventually broke it regardless of individuals	Paul Kennedy, Melvyn Leffler
The 1989 revolutions	The popular uprisings in Eastern Europe, enabled by Helsinki human rights norms and Gorbachev’s non-intervention, drove the end	Timothy Garton Ash

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4.5 The Fall of the Berlin Wall (1989) and Dissolution of the USSR (1991)

The Revolutions of 1989:

• Poland: Solidarity movement (led by Lech Walesa), legalised 1989; semi-free elections; Tadeusz Mazowiecki became the first non-Communist Prime Minister in Eastern Europe (August 1989)
• Hungary: Communist government opened its border with Austria (May 1989) — thousands of East Germans fled through Hungary to West Germany; Hungary held free elections
• East Germany: Mass demonstrations, especially in Leipzig; Erich Honecker resigned; the Berlin Wall fell on November 9, 1989 — crowds tore it down after a confused announcement that East Germans could travel freely
• Czechoslovakia: The “Velvet Revolution” — peaceful mass demonstrations; Communist government resigned; playwright and dissident Vaclav Havel became president
• Romania: The only violent revolution — Nicolae Ceausescu’s security forces fired on demonstrators; Ceausescu and his wife were tried and executed on Christmas Day 1989
• Bulgaria and Albania followed in 1989–1990

Why the Wall fell:

• Gorbachev refused to authorise Soviet intervention — the decisive factor
• East Germany’s economy had collapsed; the government had lost legitimacy
• The Hungarian border opening had already created an uncontrollable refugee flow
• A miscommunication at a press conference (an East German spokesman announced new travel rules were effective “immediately, without delay”) caused crowds to rush the Wall checkpoints — guards stood aside

German Reunification (October 3, 1990):

• West Germany (Federal Republic) absorbed East Germany (German Democratic Republic)
• A condition accepted by Gorbachev in exchange for German neutrality guarantees (though NATO membership of reunified Germany was ultimately accepted)

Dissolution of the USSR (December 25, 1991):

• After a failed coup attempt by Communist hardliners (August 1991), the Soviet Union rapidly disintegrated
• The 15 Soviet republics declared independence
• On December 25, 1991, Gorbachev resigned as President of the USSR; the Soviet flag was lowered over the Kremlin for the last time
• Boris Yeltsin became president of the Russian Federation

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Watch: Détente and the End of the Cold War

Crash Course · 12 min · The end of the Cold War — Gorbachev, Reagan, the 1989 revolutions, and the dissolution of the Soviet Union

Quick Recall — Section 4

Try to answer without scrolling up:

1. What did each of the three Helsinki Accords “baskets” cover, and which had the most significant long-term impact?
2. What factors led to the collapse of détente by 1979–1980?
3. Why did Gorbachev’s reforms lead to the collapse of the USSR rather than its renewal?

Reveal answers

1. The three baskets covered: (1) security — recognition of existing European borders; (2) economic cooperation — trade and technology exchange; (3) human rights — commitment to fundamental freedoms. The human rights basket had the most significant long-term impact, providing legal standing to dissident movements like Charter 77 (Czechoslovakia) and Solidarity (Poland) that challenged Communist governments.
2. Collapse of détente resulted from: Soviet interventionism in Africa (Angola, Ethiopia); Carter’s human rights pressure on the USSR; the Iranian Revolution removing a key US ally; the failure to ratify SALT II; and decisively, the Soviet invasion of Afghanistan in December 1979, which Carter called a fundamental threat to détente.
3. Glasnost released political forces — nationalism in Soviet republics, demand for democracy — that Gorbachev had not anticipated and could not control. Perestroika disrupted the command economy without replacing it with a functioning market, producing shortages and economic chaos. These reforms delegitimised the Soviet state rather than renewing it, accelerating the independence movements that broke up the USSR.

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Section 5: Paper 2 Exam Technique

5.1 Understanding Paper 2 Format

Paper 2 tests your ability to write analytical historical essays under timed conditions. There are no sources — this is pure essay writing from memory.

Format:

• 90 minutes total
• Write TWO essays from the topics studied
• Each essay: 15 marks
• Recommended time: 5 minutes planning + 40 minutes writing per essay

Mark bands (simplified):

Band	Marks	Description
1	1–4	Narrative/descriptive; little analysis; inaccurate or very limited knowledge
2	5–8	Some relevant knowledge; attempts analysis; lacks focus on the question
3	9–11	Mostly accurate knowledge; some consistent analysis; partial answer to the question
4	12–14	Accurate and relevant knowledge; consistent analysis; clear answer to the question with some support
5	15	Comprehensive knowledge; sustained analysis; well-structured argument; explicitly addresses all aspects of the question; may include historiography

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5.2 Command Terms

IB History Paper 2 uses specific command terms that tell you what kind of answer is expected.

Command Term	What It Requires
Discuss	Present multiple perspectives on a topic; consider different aspects; come to a conclusion
To what extent	Partially agree/disagree; acknowledge the claim in the question has merit; present evidence for and against; reach a qualified conclusion
Compare and contrast	Explicitly identify similarities AND differences between two cases; do not simply describe each separately
Evaluate	Weigh the evidence; assess the relative importance of factors; reach a judgment
Examine	Investigate and consider carefully; analyse different aspects
Analyse	Break down into components; discuss causes, consequences, and interrelationships

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5.3 Essay Structure

A strong Paper 2 essay follows a clear structure:

Introduction (5–8 sentences):

1. Contextualise the question briefly
2. Define any key terms in the question
3. State your argument (thesis) — your answer to the question
4. Briefly indicate the main points you will develop
5. Reference the examples or case studies you will use

Body paragraphs (3–4 paragraphs): Each paragraph should:

• Open with a topic sentence that makes a clear analytical point linked to the question
• Provide evidence (specific facts, dates, events, statistics)
• Analyse — explain how the evidence supports your point
• Link back to the question and your thesis

Conclusion (5–6 sentences):

• Summarise your argument (do not introduce new evidence)
• Give a clear, direct answer to the question
• Qualify your conclusion where appropriate — acknowledge complexity

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5.4 Cold War Historiographical Perspectives

Examiners reward engagement with historical debate. For Topic 12, the key interpretations are:

On the origins of the Cold War:

• Orthodox/traditionalist view: The USSR was the aggressor; Stalin’s expansionism forced the USA into a defensive response. Associated with: early Western historians writing in the 1950s–60s (William Hardy McNeil)
• Revisionist view: The USA was equally or more responsible; economic imperialism and Truman’s atomic diplomacy provoked Soviet defensiveness. Associated with: William Appleman Williams, Gar Alperovitz
• Post-revisionist view: Both superpowers shared responsibility; both pursued their own interests and misunderstood the other. Associated with: John Lewis Gaddis (early work), Melvyn Leffler
• Post-Cold War synthesis: Based on newly opened Soviet archives, scholars like Vladislav Zubok and John Lewis Gaddis (later work) argue that Stalin genuinely sought expansion, not merely security, but that Western policy also contributed to mutual misperception

On the end of the Cold War:

• Reagan won it: US military pressure and SDI broke Soviet finances (Schweizer, Richard Pipes)
• Gorbachev’s agency: Individual leadership decisions, not structural forces, determined the specific form the Cold War’s end took (Archie Brown, in particular)
• Structural collapse: Soviet economic exhaustion made collapse inevitable regardless of individuals (Paul Kennedy, “rise and fall of great powers” thesis)

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Section 6: Practice Questions

6.1 Paper 2 Style Questions — Full List

The following questions are modelled on past and specimen IB History Paper 2 questions for Topic 12. Practice these under timed conditions (40 minutes each).

Origins and nature questions:

1. “Ideological differences were the main cause of Cold War tensions between 1945 and 1953.” Discuss.

2. To what extent was the USA responsible for the origins of the Cold War?

3. Compare and contrast the foreign policies of Truman and Stalin in the period 1945–1953.

4. Evaluate the significance of the nuclear arms race in shaping the nature of the Cold War.

5. “The Cold War was inevitable given the ideological differences between the superpowers.” To what extent do you agree?

Crises questions:

6. Examine the causes and consequences of the Berlin Blockade (1948–1949).

7. “The Cuban Missile Crisis was the result of Soviet aggression.” To what extent do you agree?

8. Compare and contrast two Cold War crises in terms of their causes and outcomes.

9. Evaluate the role of miscalculation in causing Cold War crises. Refer to at least two examples.

10. “The Korean War demonstrated the limitations of containment as a US foreign policy.” Discuss.

Leaders questions:

11. To what extent did Khrushchev’s leadership increase Cold War tensions?

12. Evaluate the role of Gorbachev in ending the Cold War.

13. Compare and contrast the Cold War policies of two US presidents.

14. “Individual leaders, not structural factors, were the main cause of Cold War crises.” To what extent do you agree?

15. Examine the impact of domestic politics on the Cold War policies of either the USA or the USSR.

Détente and end of the Cold War questions:

16. Evaluate the success of détente in reducing superpower tensions in the period 1969–1979.

17. “The Cold War ended because of Soviet economic failure, not US pressure.” To what extent do you agree?

18. Examine the significance of the Helsinki Accords (1975) for the eventual end of the Cold War.

19. Compare and contrast the reasons for the beginning and the end of the Cold War.

20. To what extent was the end of the Cold War a victory for the USA?

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6.2 Model Answer Outlines

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6.3 Comparative Analysis: The Cold War Across Regions

Many Paper 2 questions require examples from more than one region. The Cold War was genuinely global — here is a framework for structuring cross-regional comparisons:

Region	Key Events	US Role	Soviet Role
Europe	Berlin Blockade, Berlin Wall, Prague Spring	NATO, Marshall Plan, Berlin Airlift	Warsaw Pact, Eastern European satellite states
East Asia	Korean War, Vietnam War	Containment; 500,000 troops in Vietnam	Arms/advisers to North Korea; arms to North Vietnam
Latin America	Cuban Missile Crisis, Chilean coup (1973), Nicaraguan Contras	Bay of Pigs, CIA-backed coups, Reagan Doctrine	Cuba as proxy; military/economic support for Castro
South Asia / Middle East	Soviet invasion of Afghanistan	Arms to Mujahideen via Pakistan	Direct military occupation of Afghanistan
Africa	Angolan Civil War, Ethiopian conflict	Support for anti-Communist factions	Cuban proxies; direct Soviet arms and advisers